1. Field of the Invention
The present invention is directed to a process for blowing oxygen-containing gas, with and without solid material, on a metal melt in a metallurgical vessel, a process for generating a burner flame and corresponding devices.
2. Description of Related Art
Processes and devices by which oxygen is blown on a metal melt and by which the melt can be heated by admixing fuel are known. For example, European Patent publication 0 584 814 A2 discloses a top-blow lance with a Laval-type mouth construction and bore holes though which a combustible medium is injected into the main flow of the lance. The main flow, comprising oxygen or oxygen-containing gas, exits the lance nozzle at supersonic velocity, but under conventional flow conditions. The lance disclosed in this reference has a water-cooled jacket but does not provide a device for injecting solids.
Installations in which solids may be added ordinarily have addition devices. For example, German Patent publication 20 26 780 C2 discloses an addition hopper which is inserted in the cover of the vessel and through which solid material--in this case, scale as oxidizing agent--may be added to the melt.
German Patent publication 29 18 213 C2 discloses a process and a device for metallurgical treatment of metal melts in which a multiple-phase treatment is made possible in a single device in which, while retaining the closing hood, at least a first device--an electrode, in the present case--which is guided through the cover is replaced by a second device, in this case a fresh lance.
It is the object of the present invention therefore to provide a process and a lance suitable for such process as a unitary structural component part in which, in a simple design and without structural conversion, various different process steps in the treatment of metal melts in a metallurgical vessel may be performed while increasing the insertion rates of the individual media.